Liquid-level gauge



May 225, 1928. 1,670,578

B. P. JOYCE LIQUID LEVEL GAUGE Filed April 6, 1925 Patented May 22, 19 28. UNITED STATES PATENT OFFICE.

BRYAN P. JOYCE, F DAVENPORT, IOWA.

mourn-LEVEL GAUGE.

Application filed April 6, 1925. Serial No. 21,196.

My invention relates to improvements in rise to various distances in the gauge glass 6. gauges used for determining the level of The bod 1 must be located above the liquid in remote tanks or tanks which are lowest liqu d level of the tank 5, and in the not easily accessible, the device being pripresent disclosure is located above the tank 60 6 inarily intended for use upon automobiles There is thus the force of gravity, tend for determining the level of fuel in the fuel ing to equalize the levels of liquid in the tank, whether the machine be of the gravitytank and the chamber 3, exerting a force fed type, or vacuum fed. to move the diaphragm 2 toward said cham- One object of the invention is to provide her 3, said force of course varying accord- 65 a new and improved form of indicator which ing to the level of liquid in thetank, and is operated partially by gravity and parincreasing proportionately with lowering of tially by barometric pressure, and a further said level, and the level of the liquid in the aim is to provide a novel, simple, inexpengauge glass 6, is the indicating medium, sive and eflicient construction for effectively such level co-operating with an appropriate 70 utilizing gravity and barometric pressure to scale 7.

vary the reading of the gauge, proportion- In the preferred form of construction, ately with variance of the liquid level in the body 1 is formed of front I and back the tank. plates 8 and 9 respectively, having annular A still further object ,is to make novel flanges 10 telescoping with each other and 7 provision for damping the action of the held together by a ring nut 11, a gasket 12 indicator, that is, preventing excessive fiuctbeing provided to establish an air-tight seal uation thereof. between the two sections of the body. The With the foregoing in view, the invention diaphragm 2, which is preferably of the corresides in the novel subject matter hereinrugated type shown, is preferably secured in 80 after described and claimed, the description place between the plates Sand 9, by having being supplemented by the accompanying its edge portion clamped between the inner drawing. edge of one of the flanges 10, and an annu- Figure 1 is a side elevation showing the lar shoulder 13 formed on the other flange. application} of the invention to the fuel Preferably, portions of the plates 8 and 9 85 feeding system of a gravity-fed automobile. are disposed in sufliciently close proximity Figure 2 is a face View of the indicator. to the diaphragm, to limit its movement in Figure 3 is a vertical sectional view on either direction, consequently limiting the line 33 of Fig. 2. rise and fall of the liquid in the gauge glass Figure 4 is a sectional view through the 6, to the high and low marks on the scale 7. 90 liquid chamber which serves to prevent ex- An upper lug 14 and a lower lug 15, are cessive fluctuation of the device. formed integrall with and ro ect for- The drawing above briefly described may wardly from the ront plate 9, tlie lower end be considered as disclosing the preferred of the gauge glass 6 being suitably secured form of construction, although variations as at 16 in a recess in the upper side of 95 can be made within the scope of the inven said lug 15. This lug is also formed with tion as claimed. a port 17 placing the gauge glass in com- The numeral 1 designates, in a general munieation with the chamber 4. A bushing way, a hollow body whose interior is divided 18 has been shown fitted within an opening by a flexible wal or diaphragm 2 into a 19 in the lug 14 and surrounding the upper 1 pair of chambers 3 and 4. By a suitable end of the gauge glass to hold the latter in passage, the chamber 3 is placed in comproper place. Threaded upon the upper munication with the liquid-containing porend of this bushing, a cap 20 has been distion of a tank 5, and said passage and chamclosed, provided with an opening 21 which her are entirely filled with liquid, and morepermits air to freely enter and leave the 1 over, are sealed against the entrance of air. glass 6.

The chamber 4 is in communication with I have shown the lower end of the back a gauge glass 6, the point of communication plate 9 formed with an integral neck 22 being at the lower end of said gauge glass suitably coupled as at 23 with a pipe 24, the while the upper end of the latter is open to lower end of this pipe being coupled as at 110 the atmosphere. This chamber 4: is also 2 5 to the lower end of a relatively large filled with liquid, the latter being adapted to liquid containing casing 26. This casin'g is vertically elongated and at its u per end is coupled at 27 with a tube 28 leading from the tank 5, the upper end of the casing 26 being also connected at 29 with the fuel intake 30 of a carbureter, in the present showing. This arrangement is used when the carbureter is supplied by gravity, and when the indicator is to be operated in connection with a vacuum-fed machine, the casing 26 will of course be coupled to the gas line leading to the vacuum tank. The casing 26 contains such an amount of fuel, that such fuel is practically unaffected by the flow of fuel to the carbureter, so that the pressure within the chamber 3 is not continually pulsating, but can only slowly change, as the level in the tank 5 varies.

To further assist in preventing undue fluctuation or pulsation of the diaphragm 2, and consequent fluctuation of the liquid in the gauge glass 6, I prefer to provide a plug 31 in the neck 22,'said plug having a small port 32 through which the liquid must pass. The size of this port is such that the liquid cannot rush rapidly through it in either direction, to have an undesirable, quick action upon the diaphragm 2.

The chamber 4 is filled 'with any suitable liquid, preferably colored, and one which will not easily evaporate and possesses low viscosity, is preferably employed. This liquid may be introduced in any convenient manner, the air being of course exhausted from the chamber 4 as the liquid is admitted. The chamber 3 and its communicating means with the tank, are totally filled with the same liquid as that contained by the tank, and for the purpose of exhausting the air from these parts to efl'eet filling thereof, I have shown a plug 33 in Fig. 3. This plug is of course air-tlght when replaced after filling of the system, and as no air can enter the chamber 3, all liquid cannot gravitate therefrom, even should the tank 5 be entirely emptied. The infinitesimal quantity ofliquid which will run from the pipe 24 under such a condition, is received in the casing 26 and entrapped therein, so that the lower end of the pipe 24 is never uncovered to permit entrance of air.

The parts of the device are so related that when the tank 5 is full of liquid, the diaphragm 2 bears against the inner side of the ront plate 8 and the liquid level in the gauge glass 6 is then at the highest point on the scale 7. As the level in the tank 5 lowers, the liquid-in the chamber 3 and pipe 24 have a tendency to lower also by gravity, 1 thus shifting the diaphragm toward the back plate 9, enlarging the chamber 4 and permitting the barometric pressure on the liquid in the gauge glass 6, to drive such liquid from the glass in sufficient quantity to always keep the chamber 4 full, regardless of the size to which this chamber is enlarged by movement of the diaphragm 2. By the time the liquid level in the tank 5 has lowered to a serious extent, the diaphragm 2 has moved until thechamber 4 is enlarged to the maximum and the level of the liquid in the gauge glass 6 is at the low point on the scale 7. The diaphragm 2 then rests against the inner side of the back plate 9.

Excellent results are obtainable from the details disclosed and they are therefore preferably followed. However, within the scope of the invention as claimed, numerous modifications may be made.

I claim In a liquid level gauge operated partly by barometric pressure and partly by gravity, the combination with a liquid tank, of a liquid-filled chamber above the lowest liquid level of said tank and having a movable wall, a liquid-filled tube placing said chamber in communication with the liquid containing portion of the tank, a portion of said tube being reduced for throttling, said liquid-filled chamber .and liquid-filled tube being sealed against entrance of air, a portion of said tube being below its point of communication with the tank in order that barometric pressure may keep the chamber and tube full of liquid, both sides of said movable wall being sub jected to barometric pressure, means for limiting the movement of the movable wall, and means for indicating the movement of said movable wall, together with a carbureter feed tube connected with and communicatin'g with the first-named tube, said portion of said first-named tube below its point of communication with the tank, including a relatively large chamber at the connection of the two tubes, said chamber being in free open communication with both of said tubes and containing the same liquid as the latter, said chamber being adapted to prevent excessive fluctuation of said movable wall by flow of fuel to the carbureter.

In testimony whereof I have hereunto affixed my signature.

BRYAN P. JOYCE. 

